Fluid drive



2 Sheets-Sheet 1 ATTORNEYS R. M. NELDEN FLUID DRIVE Allg. 20, 1963 FiledJune 25, 1960 Aug. 20,1963 R. M. NELDEN 3,100,966:

FLUID DRIVE Filed June 23, 1960 2 Sheets-Sheet 2 TOR.

INVEN RICHARD M. NELDEN w1LsoN,Lew\s MCRAE ATTORNEYS.

United States Patent O 3,100,966 FLUID DRIVE Richard M. Nelden,Birmingham, Mich., assignor to American Radiator & Standard SanitaryCorporation,

New York, N.Y., a corporation oi Delaware Filed June 23, 196i), Ser. No.38,160 8 Claims. (Cl. ell-54) This invention relates to va fluid drive,and particularly to a variable 'speed uid drive having improved meansfor partially or Wholly declutching Ithe runner during periods ofimpeller acceleration and .output shaft overload. In conventional duiddrive arrangementsoi the variable :speed type there is employed a vanedimpeller and a lvaned runner cooperating together to deiine a workchamber, Thel impeller is carried by the input shaft which may bedirectly or indirectly driven by a prime mover such `as an electricmotor or gasoline engine.Y The runner -is connected to the output sha-ftywhich drives the load. A .iluid-conning casing extends around andbeyond the impeller and runner to define a. chamber for receiving thepower lduid from :the work chamber. This receiving chamber houses afluid-withdrawing means which in the usual case consists of one :or morescoop tubes which `dip into the -iluid within the chamber Iand conveythe uid out of the fluid coupling and thence into `a sump. The sumpsupplies hot fluid to a pumping mechanism which circulates all or part`of the tluid through -a cooler structure before returning it` into thework chamber defined by the aforementioned runner and impeller.

It will be understood thatthe dri-ve from the yaned impeller to thevaned run-ner is derived from the rapidly whirl-ing or vorticallytravelling iluid located with-in the work chamber. With relatively smallquantities of fluid Within the work chamber the motion of the impelleris only partially transmitted to the runner, ie., there is a slippage,which may vary depending on the fractional extent to which the workchamber is iilled. When the work chamber is completely lilled the slipis at a minimum, and there is substantially a fone-to-one drive from theimpeller to .the runner.

The fluid level in the work chamber is determined by the position of thepreviously mentioned scoop tubes which are -located in the scoopchamber. In the usual case an externa-l control is provided `fordetermining the position of these scoop tubes, the arrangement beingsuch that when the control is suitably operated to dispose the lips ofthe scoop tubes adjacent the outer periphery of the scoop chamber thefluid level is reduced so as to correspondingly reduce the operatinglevel in the work chamber. When the control is actuated to dispose thescoop tube lips away from the :outer periphery of the scoop chamber thelevel of `the tluid ring is increased so `as-to accordingly increase the@lling of the work charnber and thereby reduce the slip existing betweenthe imeller and runner.

During certain operational periods of the lluid drive, as tor --exampleduring periods `of impeller acceleration and during other periods ofoutput shaft overload, it is desirable to partially or wholly disconnectthe -impeller [from .the runner. The impeller-runner connection is, aspreviously explained, provided by the iluid within the work chamber, andaccordingly the declutching action is necessarily obtained by anemptying of the work chamber. `It will be understood that as `anoverload condition occurs on the output shaft the emptying of the workchamber should be eiiected rather rapidly in order to prevent breakage4or wear of parts in the power system.

Also, Ithe iluid declutching :action should preferably be 3,100,966Patented Aug. 20, 1963 :automatic and without necessity for actuation byhuman intervention or human control.

lt is an object of the present invention to provide a uid drive with Iadeclutching mechanism having the above-mentioned desirable automaticcharacteristics.

A `further `object of the invention is to provide a fluid drive with :atorque limiting or declutching mechanism which is of relatively simpleconstruction and which, without extensive redesign, can be built to comeinto play at any desired percentage of slip between the impeller andrunner.

It is a further object ofthe invention to provide a fluid drive with yaVdeclu-tching mechanism, the design of which is such as to permit it toempty the work chamber quickly or more slowly, the exact rate ofemptying being varied by means of an easily effected structuralalteration of the mechanism. f

A further object of the invention is to provide a declutching mechanismwhich can be operatively utilized with a variable speed fluid drive,`and which during normal operation of the lluid drive is ineffective tohave any dlsadvantageous action on the fluid drive performance.

A general object of the invention is to provide a iiuid drive with adeclutching device having low manu-factur- .ing and maintenance costs.

Other objects of this invention will appear in the l followingdescrip-tion and appended claims, reference being the coupling show-n inoperative posi-tion in a Huid circul-ating system;

FIG. 2 is a sectional view taken substantially on line 2-2 in FIG. l. Y

Before explaining the present invention in detail, it is to beunderstood that thel `invention is not limited in its applica-tion tothe details of construction and arrmgement of parts illustrated in the`aoco-mpanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways'.Also, it is to be understood that the phraseclogy or terminologyemployed herein is Ifor the purpose of description and not oflimitation.

Referring to FIG. 1 of the drawings, there is disclosed ya fluid driveincluding :a bottom or base wall 10 having an opstanding casingstructure v12 secured thereto. The casing :structure comprisesca topWall 14, a pair of side walls 16, and a pair of end walls or bells. 18and 20. The end bells are removably but ixedly carried on vertical-vvall structures v22. and 24, the arrangement being such as to permit:the end bells to be removed for inspection, replacement `and repair of4the fluid coupling components disposed within the casing structure.

End bell '18 mounts the beaming assembly 26 Ifor the input shaft 28. Endbell 20 mounts the bearing assemblies 30 and 31 for the output shaft 32.-Bell 20 comprises two component parts numbered in the drawings as 21and 23. Component 21 mounts `anti-friction bearing :assembly 30 forshaft 32, and component 23 mounts sleeve bearing `31 for shaft 32. Itwill be understood Ithat the bearingcnd lbell relationships can bevaried, and that the `showings in the drawings are merely illustrative.The illustrated input shaft 28 is hanged `as at 314 to -form ya mountrior the impeller casing 316 and impeller 3S. As shown in FIG. 1 theimpeller casing extends beyond the impeller `and is of a two-sectionconstruction. Section 42 of the casing extends inwardly as at 44, and `apartition 48 is suitably carried on the casing so `as to cooperatetherewith `in deining a scoop chamber 46. A series of an ex-ternalcon-trol `structure.

3 openings 5G are provided at the periphery of the partition to permitfluid to flow into the scoop chamber from the work chamber.

The work chamber is definedtby the `aforementioned impeller 33 and therunner 52, each of the impeller and runner having la series of radialvanes as at 54 and Se, said vanes being radially arranged as in theconventional practice.

`In the illustrated embodiment the work chamber defined by the impellerand runner is supplied ywith workinguid from a lluid lline 53, said lineybeing connected to the work chamber via `an annular chamber 6tlg apassageway 62 within the input shaft 2S, and a passageway X64 locatedwithin the impeller. It will be understood that during rotation of theinput shaft the fluid which is introduced into the space betweenimpeller vanes 54 is given a vortical or whirling motion as indicatedgenerally by :the arrows 65.

The huid is thrown centrifugally outwardly and travels between theimpe-ller and runner vanes `so as to ltransmit power from the impellerto the -runner. Fluid occupies the annular space `68 and circulatesthrough the openings Stb into the :scoop chamber 46. The level of fluidwithin the scoop chamber is determinative of the amount or" fluid withinthe work chamber, and las previously explained, the amount `of fluid 'inthe work chamber determines the extent of slip which exists between theimpeller and runner,

To control and vary the quantity of lluid within the work chamber Iands-coop chamber there is provided a fluid-withdrawing means, shown in theillustrative embodiment as a Iscoop tube 76, said tube being of hollowcon- `struction andhaving la lip area 72 which dips into the scoop tubelluid into the `sump designated generally by the numeral 86. The exactconstruction and mounting of the lscoop tube may Ibe varied insofar `asthe present invention is concer-ned.

Thetentire system is installed with a sufficient amount of fluid Itoprovide a sump liquid level 87 su'icient to form a source of lluid vforthe fluid pump 88. lhe pump may be of various different constructions,las for example `a vane type construction, land may be powered inlvarious different way-s. One convenient method of powering the pumpconsists of employing a chain 90 trained around a sprocket 92 on inputshaft t28 and a `sprocket 94 on the pump shaft 96. The pump may besupplied with liquid through a port adjacent its lower end, and theliquid output may be directed through -a conduit `98 into the-conventional cooler |100. The cooled fluid may be then directed intothe aforementioned line 58 and thence back to the impeller via theaforementioned passageways 62 and 64. A

suitable diverter valve 59 may be provided for Adirecting V77, the teethof which mesh with the teeth of a toothed Y operator rack lill carriedon a slidable shaft lll-3. lt will be understood that the rack-shaftmeans extends through and within the end bell 2li so as to be moved byThis control structure may merely consist of a manually operable handleor actuator, or it may be operate-d automatically in response tovariation in a particular control condition such as temperature changeor fluid pressure development. The present invention is not concernedwith the type of control structure employed, and hence details thereofIare not illustrated.

` which is provided with la passage `82 -for directing the It will beunderstood that while the drawings show the fluid-withdrawing device asconsisting of a rotary scoop tube 70, yet other types offluid-withdrawing constructions such as rectilinearly mov-able scooptubes can be employed. irrespective of the type of fluid-withdrawingmeans which is employed, it will be seen that during operation of thefluid drive the torque transmission from the iimpeller to the runner isdetermined by the amount of fluid in the scope chamber. With anysubstantial quantity of fluid in the work chamber, acceleration of theinput shaft applies an added load on the output shaft. However, with theconstruction of the present invention .special provision is made foravoiding any undesired load onto the output shaft during thisacceleration period. In this connection it will be noted that the runneris provided with a series of protruding wall portions 104 arrangedaround its periphery. These wall portions are bored out to form theshort circumferentially extending passageway sections lilo. Longerradial passage sections ltlt extend from sections 16",?, and short axialpassage sections lll@ extend from the radial sections. The threeconnected sections ltl, lli and 1l@ constitute a passage` way hereindesignated by numeral 195.

ln operation of the fluid drive, during periods of input shaftacceleration the impeller is rotating faster than thel runner and thefluid which is discharged into the annular space 63 is constantlyovertaking the passage sections 166.

The velocity head of the fluid in space 68V is at this timeV sufcient toforce the fluid to ilow into the passage sections ltl and thence bedirected axially as at 110 out of the Vfluid coupling. The passagewayfluid may be discharged into the sump, either directly through thecasingeye lll or by first discharging into the scoop chamber. The natureof the discharge from passage sections liti depends on such factors asthe magnitude of the velocity head, the magnitude of the centrifugalhead, and the size `of the pasageway. `In the illustrated embodimenteach of the passage sections dit) is formed by an annular insert nozzleelement 13, and it lwill be understood that all or some of thepasageways ltl may be effectively varied in size by suitable nozzleelement construction procedures. By this arrangement lluid couplingshaving different operating characteristics can be obtained fat very lowadded cost. c

In use of the illustrated drive, during the acceleration period theamount of lluid within the work chamber will be somewhat less than thelevel which would ordinarily be dictated by the scoop tube 7@ (due tothe action of the passageway There will therefore be a substantialdeclutching of the 'runner such as to provide a torque limiting actionsufficient to safeguard the output shaft land provide a softsatisfactory acceleration action.

It will be understood that as the fluid drive comes up to speed therunner speed will approcah the impeller speed and the lluid within thespace 63 will not have sufcient velocity head to overtake the passages105. The passages will thereby not interfere with the normal operationof the lluid drive under usual operational conditions.

As previously explained, in the presence of certain overload conditionson the output shaft it is desirable to declutch the runner from theimpeller in order to prevent parts damage. With the illustrated device,in the event of an overload condition on the output shaft 32 the runnerwill necessarily reduce its speed, and the fluid within the space 68will thereby be permitted to overtake the passageways lliS and flowinwardly therein so as to be discharged from the working circuit. Thesubtraction of the fluid from the work chamber through the passagewayslt' serves to partially or wholly declutch the runner from the impellerand thereby prevents the overload condition on shaft 3-2rrfrom havingany adverse effect on the component mechanisms. Y

The time period necessary for effecting this declutching action isdetermined by the size and length of the passageways in relation to theother mechanisms of the fluid drive, and it will be understood that ingeneral the speed of declutching may be increased by increasing the sizeof the passageways and decreasing their length. The size of thepassageways may be increased by increasing the total number ofpassageways and/ or increasing the crosssectional area of eachpassageway. In the illustrated construction the cross sectional area ofeach passageway may be readily controlled by utilizing appropriate sizeinserts 113.

By choosing a suitable length for the passage sections 108 thedeclutching action can be set to come into play at any desiredpercentage of slip. This, if the passage sections 8 extend only a shortdistance inwardly from the outer periphery of the runner the velocityhead of the uid will be suihcient on a relatively small differentialspeed between impeller and runner to exhaust fluid from the work chamberin a manner to declutch the runner from the impeller. Under theseconditions the declutching action will take place at arelatively smallslip between the impeller and runner. By making the passage sections'108 extend further toward the axis of the fluid drive the lluid at `68must aquire a relatively large velocity head before it can sulicientlyovertake the passageways 105 so as to be exhausted from the workcircuit. Therefore, under these design conditions the declutching action-will take place at a relatively high percent of slip between the-impeller and runner.

If desired certain ones of passage sections Q08 may extend furtherradially inward than others, as for example as shown in FIG. 2 whereinfour of the eight passage sections terminate inwardly of the other four.This passage arrangement is of advantage in that it permits a gradual,smooth declutching action, i.e. at a relatively small speed dilerentialthe shorter ones of passage sections '108 become operative and at alarger speed differential the longer ones of passage sections `108become operative.

The `drawings show the exhaust passageways 1G35 directly in the body ofthe runner. However, it will be appreciated that these passages could beformed by other means. For example, these passageways could if desiredbe constructed as separate tubes fastened onto the back of the runner.With such a construction the outer surfaces of the tubes could be madeto have the desirable function of acting 4as fluid-engageable drivingvanes for the runner.

Various other changes could be made without departing from the spirit ofthe invention as delined in the appended claims.

I claim:

l. In a uid coupling, a-housing dening a liquid reser- Voir,

a toroidal work chamber within said housing comprising opposed axiallyaligned and spaced rotatable impeller and runner shells, mountedrespectively on input and output shafts,

means for continuously supplying liquid to said work chamber from saidreservoir,

a casing connected to said impeller shelland enclosing said runner shellin `spaced relation to form one wall Aof a rotatable scoop chamber,

a radial partition wall carried by said casing between said one wall andsaid runner to form the other wall of the scoop chamber and separatesaid work chamber from said scoop chamber, said casing and partitionwalls being spaced radially from said output shaft to form coaxial eyesopening from said Work chamber into said housing and thus to saidreservoir,

said scoop chamber being coaxial to said work chamber and in free liquidcommunication therewith whereby the level of liquid in said scoopchamber determines the amount of liquid in said work chamber and theslip in said coupling,

a scoop tube supported for radial adjustment in said scoop chamber landdischarging to said reservoir for 5 controlling the amount of yliquid insaid scoop chamberand thus in said Work chamber,

means for -adjusting said scoop tube,

scoop passage means extending radially inwardly through said runner froman inlet mouth in said work chamber `at the periphery of said runner toan exhaust opening in the runner hub adjacent said output shaft,

and said exhaust opening extending axially to discharge the liquidthrough said eyes and into said housing during predetermined slip whensaid impeller appreciably overruns said runner.

2. In -a lluid coupling including 4a housing delining a liquidreservoir,

a toroidal `work chamber within said housing comprising opposed axiallyaligned and spaced rotatable impeller and runner shells,

means for continuously supplying liquid to said work chamber from saidreservoir,

a casing connected to said impeller shell and enclosing said runnershell in spaced relation to form one wall of a rotatable scoop chamber,

a partition .wall carried by said casing between said one wall and saidrunner to form the other Wall of said scoop chamber,

said casing and partition walls having eyes coaxial to said work chamber4and opening from said -work chamber into said housing,

said scoop chamber being coaxial to said work chamber and in free liquidcommunication with said work chamber whereby the level of liquid in saidscoop chamber determines the amount of liquid in said work chamber andthe slip in said coupling,

a scoop tube supported for radial adjustment in said scoop chamber anddischarging to said reservoir for cont-rolling the amount of liquid insaid scoop chamber and thus in said work chamber,

and means for adjusting said scoop tube,

the improvement of overload scoop passage means extending through saidrunner yfrom an inlet mouth in said work chamber at the periphery of`said runner to Ian exhaust opening in alignment with said eyes of saidcasing and partition walls,

and said exhaust opening being oriented to discharge through said eyesVand into said housing during predetermined slip when said impelleroverruns said runner.

`3. In a lluid coupling including a toroidal work chamber comprised ofopposed mpeller and runner shells,

means for continuously supplying Working liquid to said work chamber,

a casing connected to said impeller shell and enclosing said runnershell in spaced relation to form a rotatable scoop chamber,

said scoop chamber having an eye coaxial to said work chamber,

said scoop chamber being coaxial to said work chamber land in freeliquid communication with said Work chamber whereby the level of liquidin said scoop chamber determines the amount of liquid in said workchamber and the slip in said coupling, 4

a scoop tube adjustable in said scoop chamber and discharging to saidsupply means for controlling the amount of liquid in said scoop chamberand thus in said work chamber,

and means for adjusting said scoop tube,

the improvement of a passage extending through said runner from an inletmouth at the periphery of said runner to an exhaust opening positionedradially inwardly of said inlet mouth,

and said exhaust opening being oriented to discharge through said eyeduring predetermined slip conditions when said coupling appreciablyoverruns said runner,

arcanes and means for conducting said discharged luid to said supplymeans.

4. lIn a fluid coupling including a toroidal work chamber comprisingopposed impeller and runner shells,

means for contiuously supplying Working liquid to said work chamber, Y

casing means connected to said impeller shell to orm a rotatable scoopchamber coaxial to said work chamber and in tree liquid communicationtherewith whereby the level of liquid in said scoop chamber determinesthe amount of liquid in said work chamber and the slip in said coupling,

said scoop chamber having an axial opening,

a scoop tube adjustable in said scoop chamber and discharging to saidsupply means for controlling the amount of liquidin said scoop chamberand thus said work chamber,

I and means for adjusting said scoop tube,

the improvement of scoop passage means extending through the back ofsaid runner from an inlet mouth in said work chamber at the peripherallevel of said runner to an exhaust opening centrally of lsaid runner,

and said exhaust opening being oriented to discharge through said axialopening of said scoop chamber during predetermined slip conditions whensaid impeller overruns said runner.

'5. In a fluid coupling,

a housing dening a liquid reservoir,

a toroidal work chamber in said housing comprising opposed axiallyaligned and spaced rotatable impellcr and runner shells, Y

meansfor supplying liquid to said work chamber from said reservoir,

a casing connected to said impeller shell and enclosing said runnershell in spaced relation to form one Wall of a rotatable scoop chamber,

a partition wall carried by said casing between said 'one wall and saidrunner to form the other wall of the scoop chamber,

said partition wall having an eye coaxial to said work chamber andopening from said work chamber into said scoop chamber,

said scoop chamber being coaxial to said work chamber and in free liquidcommunication with said work chamber whereby the level of liquid in saidscoop chamber determines the `amount of liquid in said work chamber and.the slip in said coupling,

a scoop tube adjustable in said scoop chamber and discharging to saidreservoir to control the amount of liquid in said scoop chamber and thusin said work chamber,

means for adjust-ing said scoop tube,

-a declutch passage extending from yan inlet mouth positioned at theperipheral level of said runner to an exhaust opening positionedradially inwardly of said inlet mouth,

and said exhaust opening being oriented to discharge through said eyeduring predetermined slip condi tions of said impeller overrunning saidrunner.

6. I-n a fluid coupling,

f a toroidal work chamber dened by opposed impeller and runner shells,

means for continuously supplying liquid to said work chamber,

casing means connected to said impeller shell and enclosing said runnershell in spaced relation to form la rotatable chamber to hold a rotatingring of liquid,

said rotatable chamber being coaxial to said work chamber and in freeliquid communication therewith whereby the level of liquid in saidrotatable chamber determines the amount of liquid in said work chamberand the slip in Said coupling,

adjustable regulating means for regulating the quantity of liquid insaid rotatable ring and thereby the amount of liquid in said workchamber,

declutch passage means extending from an inlet mouth at the peripherallevel of` said runner to an exhaust `opening positioned between saidcoupling axis and said inlet mouth,

and said exhaust opening being oriented to discharge liquid out of saidwork chamber and back to said supply means.

7. In a fluid coupling,

a toroidal Work chamber defined by opposed impeller and runner shells,

means' for continuously supplying Working liquid to said work chamber,

casing means connected to saidimpeller shell and enclosing said runnershell in spaced relation to form `an annular rotatable chamber to hold arotating ring of liquid,

said rotatable chamber being coaxial to said wonk chamber and in freeliquid communication therewith whereby the level of liquid in saidrotatable chamber determines the amount of liquid in said work chamberand the slip in the coupling,

adjustable regulating means for regulating the quantity of liquid insaid rotatable'ring `and thereby the amount of liquid in said workchamber,

a plu-rality lof declutch passages, each having an inlet mouth at aboutthe outer peripheral level of said impeller and runner shells in saidwork chamber and extending to an exhaust opening between said couplingaxis and said inlet mouth,

at least sOme of said exhaust openings being positioned nearer the axisof said coupling than others,

said exhaust openings being oriented to discharge liquid out of saidWork chamber and back to said supply means,

and means for recycling liquid discharged from said exhaust openingsback rto said work chamber.

8. n a iiuid coupling,

a toroidal Work chamber definedl by opposed impeller and runner shells,

means for supplying working liquidto said work at about the outerpenipheral level of said runnerV to an exhaust opening positionedbetween said coupling axis and said inlet mouth.

said exhaust opening being oriented to discharge liquid out of said workchamber and back to said supply means,

and means for recycling liquid exhausted from said discharge openingback to said work chamber.

References Cited in the file of this patent UNITED STATES PATENTS1,672,232 Saives June 5, 1928 2,127,738 Kugel Aug. 23, 1938 2,187,656Kicp et al Jan. 16, l1940 2,690,052 oding sept. 28, 1954 2,784,555Anderson Mar. 12, 1957 2,880,583

Sinclair Apr. 7, 1959

6. IN A FLUID COUPLING A TOROIDAL WORK CHAMBER DEFINED BY OPPOSEDIMPELLER AND RUNNER SHELLS, MEANS FOR CONTINUOUSLY SUPPLYING LIQUID TOSAID WORK CHAMBER, CASING MEANS CONNECTED TO SAID IMPELLER SHELL ANDENCLOSING SAID RUNNER SHELL IN SPACED RELATION TO FORM A ROTATABLECHAMBER TO HOLD A ROTATING RING OF LIQUID, SAID ROTATABLE CHAMBER BEINGCOAXIAL TO SAID WORK CHAMBER AND IN FREE LIQUID COMMUNICATION THEREWITHWHEREBY THE LEVEL OF LIQUID IN SAID ROTATABLE CHAMBER DETERMINES THEAMOUNT OF LIQUID IN SAID WORK CHAMBER AND THE SLIP IN SAID COUPLING,ADJUSTABLE REGULATING MEANS FOR REGULATING THE QUANTITY OF LIQUID INSAID ROTATABLE RING AND THEREBY THE AMOUNT OF LIQUID IN SAID WORKCHAMBER, DECLUTCH PASSAGE MEANS EXTENDING FROM AN INLET MOUTH AT THEPERIPHERAL LEVEL OF SAID RUNNER TO AN EXHAUST OPENING POSITIONED BETWEENSAID COUPLING AXIS AND SAID INLET MOUTH, AND SAID EXHAUST OPENING BEINGORIENTED TO DISCHARGE LIQUID OUT OF SAID WORK CHAMBER AND BACK TO SAIDSUPPLY MEANS.